textproduct: Quad Cities

KEY MESSAGES

- Post frontal regime and eventual incoming high pressure will provide fair and more seasonable weather through Friday.

- The next main chances for rain will be Saturday with another frontal passage, and possibly late Sunday night and Monday.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 242 PM CDT Wed Sep 9 2026

The latest sfc analysis was indicating broad and rather diffuse looking cool front dropping slowly down the western GRT LKS and IA ATTM, with precursor showers continuing to get shunted southward as the individual elements stream east to northeast. There may be a window when the bulk of the CWA is dry this evening, but then a digging short wave(seen on WV imagery acrs MT) rolls in and will look to kick up more showers and even a few thunderstorms along and north of the boundary acrs the southern CWA along and south of Hwy 34 after midnight. With limited instability and elevated nature to this activity, don't see much in the way of a severe weather threat late tonight.

The other challenge tonight will be the chances for some fog. If the sfc winds can stay light enough and we get enough thinning sky cover, feel there may be at least some patchy fog especially acrs the recent heavy rainfall areas. A lot of uncertainty on this with some models maintaining 5-7 KT northerly sfc winds and mid/high clouds thus not producing much fog at all. Low temps tonight ranging from the mid to upper 60s in the south, to the upper 50s in the north.

Thursday... Should be quite a bit of cloud cover form ongoing overrunning processes and ambient CU formation in the north, but do feel some improvement/clearing will occur form north to south as the afternoon progresses. Will advertise general high temps in the upper 70s to low 80s, but may be more 70s if cloud cover is more stubborn to clear especially in the south. Mostly clear with light winds under high pressure THu night allowing more of the area to dip into the 50s for low temps, and will have to keep more fog in mind especially in river valleys.

LONG TERM /FRIDAY THROUGH TUESDAY/

Issued at 242 PM CDT Wed Sep 9 2026

Friday...Most models in good agreement of migrating both sfc and upper ridging off to the east enough to allow some warming return flow acrs the region. Most areas should recover back up into at least the lower 80s with sunshine. This while upper level troffiness organizes acrs the northern plains into the upper MS RVR Valley along with underlying sfc frontogenesis for storm development acrs much of MN into the mid MO RVR Valley by Friday night. With the current progressive looking nature of the developing cold front, there may be a chance for some of this convection to bleed down into the local area late Friday night into Sat morning, if in a weakening fashion.

Saturday through Tuesday...The above mentioned front may be pushing out of the CWA by early SAt afternoon, making any showers and storms scooped up by this FROPA occurring more in the morning to midday and not the most optimum time for strong to severe storms. Pre-frontal warm and moist draw will make for a bit warmer and humid day with highs in the mid 80s to near 90 and sfc DPTs pooling in the upper 60s to around 70, but much will depend on frontal timing and these warmer conditions may occur acrs more of the southeast half of the DVN CWA, while areas from DBQ and CID and west stay in the 70s for ambient temps. Amounts of cloud cover and convective debris could also be a temp limiting factor.

A passing post-frontal ridge may then produce a short precip lull Saturday night into Sunday before signs of a more significant digging short wave or upper low acrs the northern plains amplifies steering cyclonic southwesterly flow toward the upper midwest and northwestern GRT LKS. May have to watch for convection with associated warm frontal retreat through the region Sunday night, placing the local area in a breezy warm sector for Monday with highs in the upper 80s to around 90. Heat indices may range from 95 to 100 again if low to mid 70 sfc DPTs can advect up this way. Thus local heat while a MCS or two impact the northern plains acrs to the heart of the GRT LKS like a deep summer style pattern. An eventual cold frontal push off the passing wave to the north, may bring some storm activity further southward into the local area either Monday night or into Tuesday, before we can count on a cooling post-frontal airmass and heat reprieve into the mid next week period.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1255 PM CDT Wed Sep 9 2026

With slow moving cold front continuing to sag through the area most of the rain is moving off to the south. But saying that some overrunning pockets of showers may still skirt the south off and on through tonight. The bulk of these showers should stay south of BRL until maybe after midnight when a few model solutions show a northward push of the activity and may clip BRL into the early morning hours. Still some post frontal low decks at MVFR and IFR levels affecting CID and DBQ for a few more hours, then expect a CIG improvement from north to south later this afternoon and into the evening. Sfc winds will be on the light side veering from the southwest, to west, and eventually to the north around the slow passing front through the evening. With the recent heavy rain, light winds and thinning sky cover there may be a chance for some fog late tonight but have low confidence with mixed signals by several of the latest models on how much fog or if much of any will form. Will lean toward having at least some MVFR fog mention at most of the sites from after 09z through sunrise.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.